KR101731147B1 - Sheet processing apparatus and image forming apparatus - Google Patents

Abstract

The sheet processing apparatus includes an endless belt configured to be brought into contact with an upper surface of a sheet stacked on the sheet stacking portion to carry the sheet, a shaft extending in a direction perpendicular to the sheet transporting direction, And a support for supporting the endless belt through the driving and rotating member. The support portion is configured to be swingable around the shaft, and the endless belt is raised and lowered by a support portion that is swung by the lift portion.

Description

[0001] SHEET PROCESSING APPARATUS AND IMAGE FORMING APPARATUS [0002]

The present invention relates to a sheet processing apparatus and an image forming apparatus.

2. Description of the Related Art In the prior art, an image forming apparatus such as a copier, a printer, a facsimile and a multifunction apparatus has a sheet processing apparatus in the body of the image forming apparatus and performs processing such as binding on a sheet discharged from the body of the image forming apparatus Includes configured types. An example of the sheet processing apparatus as described above is a sheet processing apparatus in which a sheet discharged from the main body of the image forming apparatus is discharged into the processing tray once and the sheet is conveyed in advance on the processing tray as described in Japanese Patent Application Laid-Open No. 2003-128315 And a type configured to align with the stacked sheets, bind the sheets into the processing tray if required, and then discharge the processed sheets onto the stacking tray.

13A and 13B are diagrams showing a configuration of a sheet processing apparatus of the prior art as described above. As shown in Figs. 13A and 13B, a trailing end stopper 108 configured to stop and position the sheet (s) P is provided at the end of the intermediate processing tray 107. Fig. The sheet P discharged onto the intermediate processing tray 107 by the sheet discharge roller 103 is conveyed by a knurled belt 1161 configured to be rotated by the sheet discharge roller 103 And the rear end stopper 108 by abutting against each other.

The shape of the knurled belt 1161 is changed by a floating roller X. That is, as shown in Fig. 13A, if no sheet bundle exists on the intermediate processing tray 107, the flow roller X does not move. In this case, the knurled belt 1161 rotates while being in contact with the intermediate process tray 107 without being deformed. In contrast, when a plurality of sheets P are stacked on the intermediate processing tray, the flow roller X is moved to deform the shape of the knurled belt 1161 as shown in Fig. 13B, Is applied from the knurled belt 1161 to the sheet bundle PA.

In the prior art sheet processing apparatus as described above, when the knurled belt 1161 is deformed, the distance between the delivery roller 103 and the flow roller X is changed. Therefore, the tension of the knurled belt 1161 is increased as compared with the case where the number of stacked sheets is small. When the tension is increased, the carrying force of the knurled belt 1161 increases correspondingly. When the carrying force is increased, the sheet P abutting against the rear end stopper 108 may be bent between the knurled belt 1161 and the rear end stopper 108, and thus the alignment of the sheet may be damaged.

As a countermeasure, it is possible to consider a method of controlling the amount of movement of the flow roller X by considering the change in the tension of the knurled belt 1161. [ However, if the hardness of the knurled belt 1161 is changed by change in ambient temperature or deterioration with time, a deviation occurs between the movement amount of the flow roller X and the conveying force. This deviation increases as the amount of movement increases. Accordingly, when the actual conveying force is smaller than the desired conveying force, the sheet P does not reach the rear end stopper 108. [ In contrast, when the actual conveying force is larger than the desired conveying force, the sheet P is bent between the knurled belt 1161 and the rear end stopper 108, and thus the alignment is damaged.

According to an aspect of the present invention, a sheet processing apparatus includes a sheet stacking portion on which a sheet is stacked, an endless belt configured to convey the sheet by being brought into contact with an upper surface of the sheet stacked on the sheet stacking portion, A drive rotating member configured to contact the inner peripheral surface of the endless belt, a shaft extending in a direction perpendicular to the sheet conveying direction, And a lifting portion configured to lift and lower the endless belt by pivoting the supporting portion, and a lifting portion configured to lift and lower the endless belt by rotating the driving rotating member and supporting the endless belt through the driving and rotating member.

Other features of the present invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features and aspects of the invention and, together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a view showing a configuration of an image forming apparatus including a sheet processing apparatus of the first embodiment; Fig.
2A is a schematic view showing a state of a finisher in a state in which a sheet is conveyed by a sheet discharge roller;
2B is a schematic view showing the state of the finisher in a state in which the sheet is discharged into the intermediate processing tray;
3 is a control block diagram of an image forming apparatus.
4 is a control block diagram of the finisher.
5A is an explanatory view showing the sheet binding operation of the finisher;
5B is a schematic view showing the state of the finisher in a state in which the bound sheet bundle is discharged to the stacking tray.
Fig. 5C is a schematic view showing the state of the finisher in a state in which the sheet bundle is discharged to the stacking tray; Fig.
6A is a perspective view showing a configuration of a knurled belt portion provided on a finisher;
Fig. 6B is an enlarged view of the knurled belt portion shown in Fig. 6A. Fig.
7A is a side view showing a configuration of the knurled belt portion.
Fig. 7B is a side view showing the gear mechanism of the knurled belt portion shown in Fig. 7A. Fig.
8A is a schematic view showing the state of the knurled belt portion in a state where the knurled belt is moved downward to a large extent;
Fig. 8B is a schematic view showing the state of the knurled belt portion in a state where the knurled belt is lowered to a medium degree; Fig.
Fig. 8C is a schematic view showing the state of the knurled belt portion in a state in which the knurled belt is lowered to a small extent; Fig.
9 is a flowchart for explaining the sheet processing operation of the finisher.
10 is a schematic view showing a configuration of a knurled belt portion provided in the sheet processing apparatus of the second embodiment;
11A is a view showing a configuration of a knurled belt portion of a second embodiment;
Fig. 11B is a side view showing the gear mechanism of the knurled belt portion shown in Fig. 11A. Fig.
Fig. 12A is a schematic view showing the state of the knurled belt portion of the second embodiment in a state in which the knurled belt is lowered to a large extent; Fig.
Fig. 12B is a schematic view showing the state of the knurled belt portion of the second embodiment in a state where the knurled belt is lowered to an intermediate position; Fig.
Fig. 12C is a schematic view showing the state of the knurled belt portion of the second embodiment in a state in which the knurled belt is lowered to a small extent; Fig.
13A is a schematic view showing a knurled belt of a conventional sheet processing apparatus;
Fig. 13B is a schematic view showing a state in which the knurled belt shown in Fig. 13A is deformed. Fig.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. 1 is a diagram showing a configuration of an image forming apparatus provided with a sheet processing apparatus of the first embodiment. 1, reference numeral 900 denotes an image forming apparatus, 900A denotes a main body of the image forming apparatus (hereinafter, referred to as apparatus main body), and 900B denotes an image forming section configured to form an image on a sheet . Reference numeral 950 denotes an image reading apparatus provided on an upper portion of the apparatus main body 900A and including a document carrying apparatus 950A. Reference numeral 100 denotes an image reading apparatus provided between the upper surface of the apparatus main body 900A and the image reading apparatus 950 An aligned finisher, that is, a sheet processing apparatus.

The image forming section 900B includes photosensitive drums (a to d) configured to form toner images of four colors, i.e., yellow, magenta, cyan, and black, and a plurality of photosensitive drums (a to d) And an exposure unit 906 configured to form an electrostatic latent image on the electrostatic latent image. The photosensitive drums a to d are driven by a motor (not shown). Each of the photosensitive drums has a primary charger, a developing unit, and a transfer charger arranged on the periphery thereof, and is unitized with them as process cartridges 901a to 901d.

The image forming portion 900B includes an intermediate transfer belt 902 that is driven to rotate in the direction indicated by the arrow and a transfer roller 902 configured to sequentially transfer the full color image formed on the intermediate transfer belt 902 onto the sheet P And a car transferring portion 903. By applying the transfer bias to the intermediate transfer belt 902 by the transfer chargers 902a to 902d, the toner images of the respective colors on the photosensitive drum are sequentially transferred to the intermediate transfer belt 902 in an overlapping manner. Thus, a full-color image is formed on the intermediate transfer belt.

The secondary transfer portion 903 is configured to abut against the secondary transfer opposing roller 903b via the intermediary transfer belt 902 so as to abut against the secondary transfer opposing roller 903b configured to support the intermediate transfer belt 902 And a secondary transfer roller 903a configured. In Fig. 1, reference numeral 909 denotes a registration roller, 904 denotes a paper feed cassette, and two-sided reference numeral 908 denotes a pickup roller configured to feed a sheet P stored in the paper feed cassette 904.

Next, the image forming operation of the image forming apparatus 900 having the above-described configuration will be described. When the image forming operation is started, first, the exposure unit 906 irradiates a laser beam based on image information from a personal computer or the like (not shown), and sequentially charges the photosensitive drum a To d) are exposed to form electrostatic latent images on the photosensitive drums (a to d), respectively. Thereafter, the electrostatic latent image is developed and visualized by the toner.

For example, the photosensitive drum (a) is irradiated with a laser beam based on an image signal having a yellow color component of the original through a polygon mirror or the like of the exposure unit 906, Thereby forming an electrostatic latent image. The electrostatic latent image of yellow is developed by the yellow toner from the developing unit and is visualized as a yellow toner image. Thereafter, the toner image reaches the primary transfer portion where the photosensitive drum (a) and the intermediate transfer belt 902 come into contact with each other in association with the rotation of the photosensitive drum (a). When the toner image reaches the first transfer portion, the yellow toner image on the photosensitive drum (a) is transferred to the intermediate transfer belt 902 by the primary transfer bias applied to the transfer charger 902a ).

Thereafter, when a portion of the intermediary transfer belt 902 carrying the yellow toner image moves, the magenta toner image formed on the photosensitive drum b in this manner until this time is transferred onto the yellow toner image on the intermediary transfer belt 902). In the same manner, as the intermediate transfer belt 902 moves, a cyan toner image and a black toner image are transferred onto the yellow toner image and the magenta toner image in an overlapping manner at the respective primary transfer portions. Thus, a full-color toner image is formed on the intermediate transfer belt 902. [

In parallel with the toner image forming operation, the sheets P stored in the paper feed cassette 904 are fed one by one by the pick-up roller 908. [ Next, the sheet P reaches the registration roller 909 and is conveyed to the secondary transfer portion 903 at a timing adjusted by the registration roller 909 to the toner image. Thereafter, the toner images of the four colors on the intermediate transfer belt 902 are transferred to the sheet P by the secondary transferring unit 903 in the secondary transferring unit 903a, that is, the secondary transferring bias applied to the transferring unit And transferred at the same time (secondary transfer).

Thereafter, the sheet P having the toner image transferred thereto is conveyed from the secondary transferring portion 903 to the fixing portion 905 while being guided by the conveying guide 920, Is passed through the fixing unit 905, the image is fixed. The sheet P having the image fixed thereon is passed through the discharge passage 921 provided on the downstream side of the fixing portion 905 and then discharged by the discharge roller pair 918, .

The finisher 100 is configured to accommodate the sheet P discharged from the apparatus main body 900A sequentially as shown in Figs. 2A and 2B, to align and bundle a plurality of accommodated sheets into one bundle, (Hereinafter referred to as "rear end") of the sheet bundle. As shown in Figs. 5A to 5C, the finisher 100 is provided with a processing unit 139 configured to carry out binding as required to discharge the sheet bundle and to load it on the stacking tray 114. Fig. The processing unit 139 includes an intermediate processing tray 107 as a sheet stacking unit configured to stack sheets to be bound, a stapler 110 configured to bind (staple) the sheets stacked on the intermediate processing tray 107, And a binding portion 100A having a non-staple-less binding portion.

The intermediate processing tray 107 is provided with a front and rear aligning plate 107 for regulating (aligning) both side edge positions in the width direction (depth direction) of the sheet conveyed into the intermediate processing tray 107 from a direction orthogonal to the depth direction of the apparatus main body 900A (109a, 109b). The rear-end aligning plates 109a and 109b are driven by the aligning motor M253 shown in Fig. 4, which will be described later, and are arranged in the widthwise direction of the sheet stacked in the intermediate processing tray 107, Direction.

The front and rear alignment plates 109a and 109b are normally moved to the receiving position where the sheet is received by the alignment motor M253 driven based on the detection signal detected by the alignment HP sensor not shown. The alignment motor M253 aligns both ends of the sheet stacked on the intermediate processing tray 107 so as to be in contact with both ends of the sheet stacked on the intermediate processing tray 107 in the widthwise direction And is driven to move the plates 109a and 109b.

A take-in paddle 106 and a knurled belt portion 116 are arranged on the intermediate processing tray 107. The take- The pull-in paddle 106 is configured to be moved downward by driving the paddle lift motor M252 shown in Fig. 4, which will be described later when the sheet is discharged to the intermediate processing tray 107, Clockwise in the timing. Thus, the sheet P is transported toward the knurled belt portion 116. The pulling-in paddle 106 does not interfere with the sheet discharged by the reverse drive of the paddle lifting motor M252 based on the detection information detected by the paddle HP sensor S243 before the sheet is conveyed to the processing unit 139, (Home position).

The knurled belt portion 116 is a knurled belt 1161 configured to convey a sheet stacked on the intermediate processing tray 107, which is rotated by a conveying motor M250 shown in Fig. And an endless sheet conveying portion (endless belt). The sheet P is pulled by the knurled belt 1161 and is arranged to align the position of the sheet P in the sheet conveying direction when the sheet P is conveyed by the pull-in paddle 106, And is brought into contact with the rear end stopper 108 to be aligned with the sheet previously loaded on the intermediate processing tray 107. [ In this embodiment, the pull-in paddle 106, the knurled belt portion 116, the rear end stopper 108 and the front and rear registration plates 109a and 109b are arranged in alignment with each other, (130).

2A and 2B, reference numeral 112 denotes a rear end auxiliary portion. The rear end auxiliary portion 112 is moved from a position where it does not interfere with the movement of the stapler 110 by the auxiliary motor M254 driven on the basis of the detection signal from the auxiliary HP sensor S244 shown in Fig. As shown in FIG. The trailing auxiliary portion 112 discharges the sheet bundle into the stacking tray 114 after the sheet bundle is bound as described below.

The finisher 100 has an entrance roller 101 and an exit roller 103 configured to blow a sheet into the apparatus and the sheet P discharged from the apparatus body 900A is transferred to the entrance roller 101. [ At this time, the sheet delivery timing is detected by the inlet port sensor S240 at the same time. The sheet P delivered to the inlet roller 101 is discharged to the intermediate processing tray 107 sequentially by the discharge roller 103, that is, the discharge portion, and thereafter is discharged to the discharge paddle 106 or the knurled belt 1161 And comes into contact with the rear end stopper 108 by the returning portion. Thus, the alignment of the sheet P in the sheet conveying direction is performed, and the aligned sheet bundle is formed.

2A and 2B, reference numeral 105 denotes a rear end dropper, and the rear end dropper 105 is pressed by the sheet P passing through the sheet discharge roller 103 as shown in FIG. 2A, do. When the sheet P passes through the sheet discharge roller 103, the rear end dropper 105 drops by its own weight as shown in Fig. 2B and presses the rear end portion of the sheet P downward from the top.

Reference numeral 104 denotes a destaticizing needle, and reference numeral 115 denotes a bundle holder. The bundle holder 115 presses the stack of sheets stacked on the stacking tray 114 by being rotated by the bundle holding motor M255 shown in FIG. 4 and described later. Reference numeral S242 denotes a tray lower limit sensor, and reference numeral S245 denotes a bundle holder HP sensor. When the sheet bundle blocks the light to the tray HP sensor S241, the tray elevating motor M251 shown in Fig. 4 is mounted on the tray HP sensor S241 until the tray HP sensor S241 becomes the light- The tray 114 is moved downward, whereby the position of the sheet surface is determined.

FIG. 3 is a control block diagram of the image forming apparatus 900. FIG. In Fig. 3, reference numeral 200 denotes a CPU circuit portion, i.e., a control portion, arranged at a predetermined position in the apparatus main body 900A and configured to control the apparatus main body 900A and the finisher 100, as shown in Fig. The CPU circuit unit 200 includes a CPU 201, a ROM 202 having a control program or the like stored therein, an area for temporarily holding control data, and a RAM (hereinafter referred to as " 203).

3, reference numeral 209 denotes an external interface between the image forming apparatus 900 and an external PC (computer) Upon reception of the print data from the external PC 208, the external interface 209 expands the data into a bitmap image and outputs the bitmap image as image data to the image signal control unit 206. [

The image signal control unit 206 outputs the data to the printer control unit 207. The printer control unit 207 outputs the data from the image signal control unit 206 to an exposure control unit not shown. The image of the original read by the image sensor not shown in the figure provided to the image reading device 950 is output from the image reader control unit 205 to the image signal control unit 206 and the image signal control unit 206 outputs the image output to the printer control unit 206. [ (207).

The operation unit 210 includes a plurality of keys used for setting respective functions related to image formation, a display unit configured to display the setting status, and the like. The key signal corresponding to the operation of each key by the user is output to the CPU circuit unit 200 and the corresponding information is displayed on the display unit based on the signal from the CPU circuit unit 200. [

The CPU circuit unit 200 is configured to control the image signal control unit 206 in accordance with the control program stored in the ROM 202 and the setting of the operation unit 210 and is controlled by the DF (original transporting unit) (See FIG. 1). The CPU circuit unit 200 also controls the image reading apparatus 950 (see Fig. 1) via the image reader control unit 205, the image forming unit 900B (see Fig. 1) via the printer control unit 207, And controls the finisher 100 through the control unit 220, respectively.

In this embodiment, the finisher control unit 220 as a control unit is mounted on the finisher 100 and performs drive control of the finisher 100 by transmitting and receiving information to and from the CPU circuit unit 200. It is also possible to dispose the finisher control section 220 on the apparatus body side integrally with the CPU circuit section 200 and to control the finisher 100 directly from the apparatus main body side.

4 is a control block diagram of the finisher 100 of this embodiment. The finisher control section 220 includes a CPU (microcomputer) 221, a ROM 222, and a RAM 223. The finisher control unit 220 exchanges data by communicating with the CPU circuit unit 200 through the communication IC 224 and executes each program stored in the ROM 222 based on a command from the CPU circuit unit 200, Thereby controlling the driving of the finisher 100.

The finisher control unit 220 includes a conveyance motor M250, a tray elevation motor M251, a paddle elevation motor M252, an alignment motor M253, an auxiliary motor M254, a bundle holding motor M255, and an STP motor M256 ) Through a driver 225. [ The finisher control unit 220 drives the non-staple binding motor M257 and the knurled motor M258 through the driver 225. [

The inlet port sensor S240, the discharge sensor S246, the tray HP sensor S241, the tray lower limit sensor S242, the paddle HP sensor S243, the auxiliary HP sensor S244 and the bundle holder HP sensor S245, And is connected to the control unit 220. A counter CT configured to count the number of sheets stacked on the medium sensor S246, the knurled belt HP sensor S247 and the intermediate process tray 107 is connected to the finisher control unit 220. [ The finisher control unit 220 drives the alignment motor M253, the knurled motor M258, and the like based on the detection signals from the respective sensors described above.

Then, the sheet binding operation of the finisher 100 according to the present embodiment will be described. The sheet P discharged from the image forming apparatus 900 is transferred to the entrance roller 101 driven by the conveying motor M250 as shown in Fig. 2A described above. At this time, the sheet transfer timing is simultaneously detected from the leading end of the sheet P by the entrance port sensor S240.

Thereafter, the sheet P delivered to the inlet roller 101 is then transferred from the inlet roller 101 to the delivery roller 103, and the front end is transported while lifting the rear end dropper 105. At the same time, the sheet P is discharged by the electrostatic charge 104 into the intermediate processing tray 107 while being discharged. The sheet P discharged into the intermediate processing tray 107 by the discharge roller 103 is held by the weight of the rear end dropper 105 from the top so that the rear end of the sheet P is held on the intermediate processing tray 107 The amount of time required to fall into the space is reduced.

Thereafter, the finisher control section 220 performs control relating to the sheet discharged to the intermediate process tray 107 based on the detection signal of the trailing edge of the sheet P detected by the sheet sensor S246. 2B, the paddle lifting motor M252 is driven to lower the pull-in paddle 106 toward the intermediate processing tray 107 and bring the paddle 106 into contact with the sheet P . At this time, the pull-in paddle 106 is rotated counterclockwise by the conveying motor M250. The sheet P is conveyed toward the rear end stopper 108 by the pull-in paddle 106 to the right in the figure and then the rear end of the sheet P is conveyed to the knot belt 1161. [

When the rear end of the sheet P is transmitted to the knot belt 1161, the paddle lifting motor M252 is driven in the reverse direction to cause the pull-in paddle 106 to move upward. When the paddle HP sensor S243 detects that the incoming paddle 106 has reached the HP, the finisher control section 220 stops driving the paddle lifting motor M252.

Thereafter, the sheet P delivered to the knurled belt 1161 is pulled by the knurled belt 1161, and the rear end abuts against the rear end stopper 108. [ After the rear end of the sheet P abuts against the rear end stopper 108 to come into contact with the rear end stopper 108, the knurled belt 1161 slips and rotates relative to the sheet P, . By this slip conveyance, the inclination of the sheet P which abuts on the rear end stopper 108 and is touched may be corrected.

The finisher control section 220 drives the alignment motor M253 to move the aligning plate 109 in the width direction of the sheet P, And aligns the position of the sheet P in the width direction. By performing the series of operations described above so that a predetermined number of sheets are repeatedly bound, the sheet bundle PA aligned on the intermediate processing tray 107 is formed as shown in Fig. 5A.

Thereafter, after the sorting operation is performed, if the binding mode is selected, the binding is performed by the binding unit. That is, when the binding is performed on the sheet bundle with the staple, the sheet bundle is bound by driving the STP motor M256 driving the stapler 110. [ When the no-staple binding is performed on a sheet bundle, the sheet bundle is bound by driving a no-staple binding motor M257 configured to drive a non-illustrated staple binding portion.

5B, the rear end portion of the sheet bundle PA is pressed by the rear end auxiliary portion 112 and the discharge claw 113, which are sheet discharging portions simultaneously driven by the auxiliary motor M254 , The sheet bundle PA on the intermediate processing tray 107 is discharged onto the stacking tray 114 in the form of a bundle.

Then, as shown in Fig. 5C, in order to prevent the sheet bundle PA stacked on the stacking tray 114 from being pressed in the conveying direction by the subsequently discharged sheet bundle, the bundle holder 115 And rotates counterclockwise to hold the rear end portion of the sheet bundle PA. When the sheet bundle PA cuts off the light to the tray HP sensor S241 after the bundle holding operation by the bundle holder 115 is completed, the tray elevation motor M251 moves the tray HP sensor S241 to the light emitting state The loading tray 114 is moved downward until the position of the sheet surface is determined. By repeatedly performing the above-described series of operations, the required number of sheet bundles PA may be discharged onto the stacking tray 114.

When the stacking tray 114 is moved downward and the light directed to the tray lower limit sensor S242 is blocked during operation, the fullness of the stacking tray 114 is detected, and the finisher control unit 220 detects the fullness of the stacking tray 114 It is noted that the CPU circuit unit 200 is notified of the full state of the stacking tray 114. [ The CPU circuit unit 200 stops forming the image when the full state of the stacking tray 114 is notified. Thereafter, when the stack of sheets on the stacking tray 114 is removed, the stacking tray 114 is moved upward until it blocks light to the tray HP sensor S241, and then the tray HP sensor S241 is turned on So that the sheet surface of the stacking tray 114 is again determined. Thus, image formation of the image forming apparatus 900 is resumed.

Figs. 6A and 6B and Figs. 7A and 7B are diagrams showing the configuration of the knurled belt portion 116 of the present embodiment. 6A and 6B, the knurled belt portion 116 includes a holder 11612 configured to hold a knurled belt 1161 and a knurled belt 1161. There are two sets of knurled belts and members associated with the knurled belt, for example, a holder 11612, a frame 11610, and first to third gears 1162 to 1164. However, Only one set of these two sets will be provided below. 7B, the knurled belt portion 116 includes first to third gears 1162 to 1164 arranged in the inside of the knurled belt 1161 and first to third gears 1162 to 1164 opposed to the first gears 1162, And a driven roller 1165 configured to sandwich the knurled belt 1161 between the guide roller 1161 and the guide roller 1162.

The knurled belt portion 116 further includes a frame 11610 shown in Fig. 7A configured to hold the first and second gears 1162 and 1163 and the rotating shafts 1166, 1167, and 1169 of the driven roller 1165 . The rotating shaft 1168 of the third gear 1164 is provided inside the knurled belt 1161 and arranged in a direction perpendicular to the sheet conveying direction of the knurled belt 1161 in parallel with the intermediate processing tray 107. [ The rotating shaft 1168 is rotatably supported by a frame 11610. [

The frame 11610 configured to rotatably support the second gear 1163 and the driven roller 1165 when the knurled belt 1161 is lifted is supported by the third gear 1164 as the support point, As shown in Fig. That is, the rotating shaft 1168 of the third gear 1164 functions as a swing shaft (elevating shaft) of the frame 11610 provided on the intermediate processing tray 107 to be rotatable (to be raised and lowered) 1164 are provided on the swing shaft of the frame 11610. [

The rotating shaft 1168 of the third gear 1164 is rotated upon receipt of the driving force from the conveying motor M250 shown in Fig. This rotation is transmitted to the first gear 1162 configured to sandwich the knurled belt 1161 with the driven roller 1165 via the third and second gears 1164 and 1163 as the drive transmission portion. The first gear 1162 as the driving rotational member and the third gear 1164 as the auxiliary rotational member contact the inner circumferential surface of the knurled belt 1161 to rotatably support the knurled belt 1161. Thus, when the conveying motor M250, that is, the shaft driving portion is driven and the first gear 1162 and the third gear 1164 are rotated, the knurled belt 1161 rotates correspondingly.

In the embodiment, the driven roller 1165 as the driven rotational member configured to sandwich the knurled belt 1161 between the first gear 1162 and the first gear 1162 is provided with a rotary part (not shown) configured to rotate the knurled belt 1161 116A. The first, second and third gears 1162, 1163 and 1164 are configured to rotate at the same speed. Accordingly, the knurled belt 1161 moves between the first gear 1162 and the third gear 1164 while maintaining a constant tension without being stretched or sagged.

In the embodiment, the knurled belt portion 116 includes two sets of first to third gears 1162 to 1164 corresponding to the two knurled belts 1161 as described above, and each set of gears And are provided at predetermined intervals on the rotating shafts 1166, 1167, and 1168. The retainer 1161a is provided in the widthwise center between the sets of gears in the width direction orthogonal to the rotation direction of the knurled belt 1161. [ Retention of the knurled belt 1161 is achieved by positioning the retainer 1161a between the two sets of first to third gears 1162 to 1164. [

The holder 11612 is fixed to a holder shaft 11613 which is configured to be driven by a knurled motor M258 capable of rotating in the forward and reverse directions shown in Fig. Accordingly, when the holder shaft 11613 is rotated, the holder 11612 rotates upwardly and downwardly. The flag 11613a is provided at one end of the holder shaft 11613 and the finisher control section 220 determines that the knurled belt 1161 is in the home position by detection of the flag 11613a by the knurled belt HP sensor S247 .

The holder 11612 includes a support shaft 11611 fixed at one end thereof to the frame 11610 so as to be locked thereto. Thereby, when the holder 11612 is rotated upward and downward, the frame 11610 swings around the rotating shaft 1168 of the third gear 1164 via the support shaft 11611, 1161 are elevated and lowered. That is, when the knurled motor M258 rotates, the holder 11612 is rotated upward and downward, and the knurled belt 1161 is brought into contact with the sheet on the intermediate process tray 107, Position and to the groove position as a separation position in which the knurled belt 1161 separates from the sheet on the intermediate process tray 107. [

The abutting position of the knurled belt 1161 needs to be shifted upward in conjunction with an increase in the number of sheets stacked in order to avoid excessive conveying force of the knurled belt 1161 in conveying the sheet. Therefore, in the present embodiment, the finisher control section 220 changes the position of the knurled belt 1161 according to the number of stacked sheets of the sheet bundle (on the sheet stacking section) on the process tray, So that the force is within a predetermined range. In other words, the finisher control section 220 controls the knurled motor M258 so that the endless belt is positioned at a position corresponding to the number of sheets stacked on the sheet stacking section.

8A to 8C are diagrams showing the state of the knurled belt portion 116 when the sheet P is carried on the intermediate processing tray 107. Fig. 8A shows a state of carrying the uppermost sheet P1. Fig. 8B shows a state in which the twenty-first sheet P21 is conveyed while 20 sheets of 64 g / m < ² > are stacked on the intermediate processing tray. 8C shows a state in which 40 sheets of 64 g / m < ² > sheets are stacked on the intermediate processing tray and the 41st sheet P41 is conveyed.

Here, in the present embodiment, the pulse motor is used as a knurled motor M258 as a driving unit configured to drive the holder 11612 as a lift portion configured to lift and lower the frame 11610. [ The amount of elevation (shaking motion) of the knurled belt 1161 moving up and down integrally with the frame 11610 is controlled by driving the knurled motor M258 in the number of pulses in accordance with the number of sheets stacked.

Thereafter, the sheet processing operation of the finisher 100 according to the present embodiment will be described with reference to the flowchart shown in Fig. When the sheet processing operation (operation) is started, the finisher control unit 220 drives the knurled motor M258. When the knurled belt HP sensor S247 detects the flag 11613a on the holder shaft 11613, the knurled motor M258 is stopped. Thus, the knurled belt 1161 waits at the home position (ST1). Thereafter, the sheet P is discharged into the intermediate processing tray 107 by the discharge roller 103 (ST2), and the sheet P is conveyed to the knurled belt portion 116 by the pull-in paddle 106 ST3).

Thereafter, the finisher control section 220 drives the knurled motor M258 and moves the knurled belt 1161 downward. At this time, the finisher control section 220 determines whether the number of sheets stacked on the intermediate processing tray 107 is within the range of 0 to 20 from the information from the counter CT (ST4). When the number of stacked sheets is within the range of 0 to 20 (Y in ST4), the finisher control section 220 increases the amount of descent of the knurled belt 1161 as shown in FIG. 8A (ST5). When the number of stacked sheets is not within the range of 0 to 20 (N in ST4), it is judged whether or not the number of stacked sheets is in the range of 20 to 40 (ST6). When the number of stacked sheets is in the range of 20 to 40 (Y in ST6), the amount of descent is reduced as shown in Fig. 8B and the amount of descent is set as intermediate (ST7).

If the number of stacked sheets is not in the range of 20 to 40 (N in ST6), it is determined that the number of stacked sheets is within the range of 40 to 50. Therefore, the descending amount is further reduced as shown in Fig. 8C, and the descending amount is set to be smaller (ST8). The driving of the conveying motor M250 is started and the knurled belt 1161 is rotated before lowering the knurled belt 1161 by an amount corresponding to the number of sheets to be stacked. Thus, when the knurled belt 1161 is lowered by an amount corresponding to the number of sheets to be subsequently stacked, the knurled belt 1161 comes into contact with the sheet stacked in the intermediate processing tray 107 while rotating, (ST9), and aligns the sheets.

When the alignment of the sheet P and the sheet previously stacked on the intermediate processing tray 107 in the sheet conveying direction by the rear end stopper 108 is finished, the finisher control unit 220 is controlled to rotate in the reverse direction by the knurled motor M258 And lifts the knurled belt 1161. When the knurled belt HP sensor S247 detects the flag 11613a of the holder shaft 11613, the knurled motor M258 is stopped and the knurled belt 1161 is held at the home position (ST10). Thereafter, the alignment motor M253 shown in Fig. 4 described above is driven, and alignment of the sheet P in the width direction is performed using the alignment plate 109 (ST11).

After the series of aligning operations is completed, the finisher control section 220 determines whether the sheet P is the final sheet (ST12). When it is not the final sheet (N in ST12), the number of sheets to be counted by the counter CT is incremented by one (ST13). When it is the final sheet (Y in ST12), the presence or absence of a subsequent binding job is judged (ST14).

When the binding operation is selected (Y in ST14), the STP motor M256 or the no-staple binding motor M257 is driven and the binding is executed by the stapler 110 or the no-staple binding unit ST15. Thereafter, the auxiliary motor M254 is driven, and the sheet bundle is discharged to the stacking tray 114 by the rear end auxiliary portion 112 (ST16). If the binding operation is not selected (N in ST14), the sheet bundle is discharged to the stacking tray 114 by the rear end auxiliary portion 112 (ST16).

In this embodiment, as described above, the amount of fall of the knurled belt 1161 is controlled by driving the knurled motor M258 in the number of pulses corresponding to the number of sheets stacked. The frame 11610 which holds the rotating shafts 1166 and 1167 of the first and second gears and the rotating shaft 1169 of the driven roller 1165 is rotatably supported by the rotating shaft of the third gear 1164 in this embodiment, (Not shown).

Thus, when lowering the knurled belt 1161 corresponding to the number of sheets to be stacked, the knurled belt 1161 descends the frame 11610 so that at least between the first gear 1162 and the third gear 1164 It can be lowered while maintaining the positional relationship constant. Therefore, the tension between the first gear 1162 and the third gear 1164 of each knurled belt 1161 can be kept constant. In other words, even if the position of the knurled belt 1161 is changed according to the number of sheets stacked, the tension of the knurled belt 1161 may be kept constant.

As described so far, in this embodiment, the rotating shaft 1168 of the third gear 1164 as the lifting shaft of the frame 11610 is provided inside the knurled belt 1161. [ The frame 11610 swings with respect to the rotating shaft 1168 of the third gear 1164 so that the knurled belt 1161 is moved in the direction of the frame 11610 And is lowered integrally. In this manner, since the knurled belt 1161 is lifted and lowered in accordance with the number of sheets stacked and rotated at a predetermined rotational speed, the circular shape can be held without deforming the knurled belt 1161 by the centrifugal force. Therefore, the tension may be kept constant.

The positional relationship (distance) between the first gear 1162 and the third gear 1164 can be kept constant even when the knurled belt 1161 is lowered according to the number of stacked sheets, 1161 are kept constant. Therefore, an increase in the conveying force can be prevented, and the position of the sheet in the sheet conveying direction can be aligned by the knurled belt 1161 without damaging the alignment of the sheet. Even when the hardness of the knurled belt 1161 changes due to a change in the ambient temperature or deterioration with time, the tension of the belt is not changed due to the movement of the knurled belt 1161, and the deviation of the conveying force can be suppressed .

Next, a second embodiment of the present invention will be described. FIGS. 10, 11A and 11B are views for explaining the configuration of the knurled belt portion provided in the sheet processing apparatus according to the second embodiment. In Figs. 10, 11A and 11B, the same reference numerals as those of Figs. 6A and 6B, Figs. 7A and 7B described above indicate the same or corresponding parts.

10, 11A and 11B, the knurled belt portion 116 is supported by the third gear 1164 on the inner side of the knurled belt 1161, And auxiliary gears 11614 and 11615 as members. The rotary shafts 11616 and 11617 of the auxiliary gears 11614 and 11615 shown in Fig. 11B are rotatably supported by the frame 11610 as shown in Fig. 11A.

12A to 12C are diagrams showing the state of the knurled belt portion 116 when the sheet P is carried on the intermediate processing tray 107. Fig. 12A shows a state in which the first sheet P1 is conveyed. 12B shows a state in which the twenty-first sheet P21 is conveyed while 20 sheets of 64 g / m < ² > are stacked on the intermediate processing tray. 12C shows a state in which 40 sheets of 64 g / m < ² > sheets are stacked on the intermediate processing tray and the 41st sheet P41 is conveyed.

Similarly, in this embodiment, the descent amount of the knurled belt 1161 is controlled by driving the knurled motor M258 in the number of pulses corresponding to the number of loaded sheets in the same manner as in the first embodiment described above. 12A to 12C, when the knurled belt 1161 is lowered in accordance with the number of stacked sheets, the knurled belt 1161 is rotated at least by the first gear 1162 and the third gear 1164 Can be lowered while maintaining a constant positional relationship between them. Therefore, even if the position of the knurled belt 1161 is changed in accordance with the number of stacked sheets, the tension of the knurled belt 1161 may be kept constant.

In the second embodiment, by the provision of the plurality of auxiliary gears 11614 and 11615, the circular shape of the knurled belt 1161 is prevented from being deformed by distortion or the like and being sagged downwardly considerably during rotation. Thus, the surface area at which the knurled belt 1161 is brought into contact with the upper surface of the sheet is increased, so that the alignment of the sheet is prevented from being damaged by the load of the knurled belt 1161 at the time of alignment with the alignment plate 109 do.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims (21)

A sheet conveying section configured to convey the sheet;
A sheet stacking portion in which the sheet conveyed by the sheet conveying portion is stacked,
An endless belt configured to carry a sheet by being brought into contact with an upper surface of the sheet stacked on the sheet stacking portion,
An aligning portion configured to align the position of the sheet in the sheet conveying direction of the sheet by being brought into abutting contact with the end portion of the sheet conveyed by the endless belt,
A drive rotation member configured to contact the endless belt to rotate the endless belt,
A shaft extending in a direction orthogonal to the sheet conveying direction,
A support portion configured to be swingable about the shaft and rotatably supporting the drive rotation member and supporting the endless belt through the drive rotation member,
And an elevating portion configured to elevate the endless belt by swinging the supporting portion. The method according to claim 1,
A driving unit configured to drive the elevating unit;
Further comprising a control unit configured to control the driving unit such that the endless belt is positioned at a position corresponding to the number of sheets stacked on the sheet stacking unit. The method according to claim 1,
A shaft driver configured to drive the shaft;
And a drive transmitting portion configured to transmit the rotation of the shaft to the drive rotating member. 4. The apparatus according to claim 3, wherein the drive transmitting portion includes a first driving force transmitting rotational member provided on the shaft and a second driving force transmitting rotational member rotatably supported on the supporting portion,
Wherein the drive rotational member receives transmission of rotation from the shaft through the first and second driving force transmission rotational members. 5. The apparatus according to claim 4, wherein the support portion rotatably supports the first and second driving force transmission rotational members, and supports the driving rotational member, the first driving force transmission rotational member, and the second driving force transmission rotational member So that the relative distances between these members are kept constant. The sheet processing apparatus according to claim 5, wherein the first driving force transmission rotational member is arranged to abut against and contact with the inner circumferential surface of the endless belt, and the drive rotational member and the first driving force transmission rotational member are configured to rotate at the same speed, . The sheet processing apparatus according to claim 1, further comprising: a driven rotation member configured to insert an endless belt between the drive rotation member and the driven rotation member, wherein the driven rotation member is rotatably supported by the support portion. The sheet processing apparatus according to claim 1, further comprising an auxiliary rotary member configured to abut against an inner circumferential surface of the endless belt, wherein the auxiliary rotary member is rotatably supported by the support portion. The image forming apparatus according to claim 1, further comprising an auxiliary rotating member configured to abut on and contact the inner circumferential surface of the endless belt,
Wherein the shaft is a rotary shaft of the auxiliary rotary member. The sheet processing apparatus according to claim 2, wherein the driving unit is a pulse motor. The sheet processing apparatus according to claim 1, wherein the shaft is provided inside the endless belt. The sheet processing apparatus according to claim 1, wherein the endless belt is in contact with an upper surface of the sheet while being deflected, thereby conveying the sheet stacked on the sheet stacking portion. A sheet conveying section configured to convey the sheet;
A sheet stacking portion in which the sheet conveyed by the sheet conveying portion is stacked,
An endless belt configured to carry a sheet by being brought into contact with an upper surface of the sheet stacked on the sheet stacking portion,
An aligning portion configured to align the position of the sheet in the sheet conveying direction of the sheet by being brought into abutting contact with the end portion of the sheet conveyed by the endless belt,
A first rotating member contacting the inner circumferential surface of the endless belt,
A second rotating member configured to contact the outer circumferential surface of the endless belt and sandwich the endless belt between the first rotating member and the second rotating member,
A third rotating member contacting the inner circumferential surface of the endless belt,
And an elevation unit configured to elevate the endless belt while maintaining a constant distance between a rotation center of the first rotation member and a rotation center of the third rotation member. 14. The method of claim 13,
A driving unit configured to drive the elevating unit;
Further comprising a control unit configured to control the driving unit such that the endless belt is positioned at a position corresponding to the number of sheets stacked on the sheet stacking unit. An image forming section,
The image forming apparatus comprising the sheet processing apparatus according to claim 1 configured to process a sheet on which an image is formed by the image forming section. 14. The method of claim 13,
The elevating unit includes:
A swingable support portion that rotatably supports the first rotating member, the second rotating member, and the third rotating member, and supports the endless belt through the first and second rotating members;
And an elevating portion configured to elevate the endless belt by swinging the supporting portion. 17. The method of claim 16,
Further comprising a shaft configured to pivotably support the endless belt,
Wherein the endless belt has a circular shape, and the center of the shaft is shifted from the center of the endless belt. 14. The method of claim 13,
Wherein the first rotating member is a gear engaged with teeth formed on an inner circumferential surface of the endless belt,
And the third rotating member is a gear engaged with the teeth formed on the inner circumferential surface of the endless belt. 14. The method of claim 13,
Wherein the endless belt rotates by receiving a driving force transmitted by the first rotating member. 14. The method of claim 13,
Wherein the endless belt is rotated and supported through the first to third rotating members. 14. The method of claim 13,
Wherein the endless belt has a circular shape, and the elevating unit lifts the endless belt by pivoting the endless belt about a swing center offset from the center of the endless belt.

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